If you wish to get admission in top NITs and in top branches like CS, ME, ECE etc then better to work hard to get 230-270 as this would be the safest range to get seat there but if you are asking for lower or average NITs then admission may be possible on 150 or above depending upon the particular NIT and branch. For reference, you can go through the below link -

Jee Main cut off

Good Luck!!!